Lead covering of electric cables and the like by extrusion



March 9 1926.

E. E. JUDGE LEAD COVERING OF ELECTRIC CABLES AND THE LIKE BY EXTRUSION 5, 1925 3 Sheets-Sheet 1 Filed' Feb.

March 9 E. E. JUDGE LEAD COVERING 0F ELECTRIC CABLES AND THE LIKE BY EXTRUSION Filed Feb. 5, 1925 3 Sheets-Sheet 2 March 9 1926. E. E. JUDGE LEAD COVERING 0F ELECTRIC CABLES AND-THE 'LIKE BY BXTRUSION 3 sheets-sheet :5

Filed Feb. 5, 1925 Patented Mar. 9, 1926.

ERNEST EDWARD JUDGE, OF GB-AVESERD, ENGLAND, ASSIGNOR T0 W. '1. HENLEYS 1,575,768 PATENT OFFICE.

TELEGRAPH WORKS comm LIMITED, OF LONDON," ENGLAND.

Lmn'covnnme or ELECTRIC GABLES AND THE LIKE BY EXTRUSION.

Applioatioxi mearebmrys, 1925 Serial No. 5,95

To all whom it may concern:

Be it known that I, ERNEST Eowann' J 110615, of 66 Pelham Road, Gravesend, in the county of Kent, England, a British subject, have invented certain new and useful Improvements in or Relating to the Lead Covering of' Electric Cables and the like by Extrusion, of which the following is a specification. v

This invention relates to the 'lead covering of electric cables by extrusion, and has for its object a ontinuous extrusion process which enables not only any desired length of cable to be sheathed but also prevents the formation of splits in the leadcovering of an electric cable, a disadvantage which has been foundto result from the? usual process of extrusion.

In accordancewith the present invention a'tubular holder for the nose or point of the die, is supportedat its rear end within and by the cylinder from which the 'lead is to be extruded, the cylinder being adapted for the charging thereinto of molten lead so that'it will unite with the lead left from the last operation.

Preferably the point-holder is sup orted' axially within the cylinder, and the orked members of the plunger are disposed substantially symmetrically around said pointholder and are united at their operative ends by a ring which presents the working face of the plunger. The cylinder or an extension thereof may be formed with one or.'more lateral apertures to enable access to be obtained to the working face when the. lunger is at the back end of its stroke,

so t at said face may be kept clean.

In the accompanying drawings Figure l is a sectional elevation of one form of extrusion machine for the lead-covering of electric cables constructed in accordance with this invention; Figure 2 is a crosssection thereof on the line 22, Figure 1; Figure 3 is a perspective view of the plunger; Fi re 4 is a similar view of the point, pointolder and its support; Figure 5 is a fragmentary section illustrating a modification; and Figure 6 is a cross section on the line 6-6, Figure 5.

In the lead cylinder a of the machine is coaxially disposed a holder I) for a. nose or point 1), the rear end of which holder is flanged at c in order that it may be bolted to the rear end of the cylinder a. At

the front end of the cylinder a are arranged the usual guide ringld, die 6, die-holder f, and a ring 9 with an inclined periphery with which coact corres ondingly inclined faces on wedge bolts h :or centralizing the die (2.

The point-holder b is tubular andprovided with a rearward tubular extension or guide 7' to give passage to the cable k to be covered. The cylinder a is connected by tie-bars mwithfa' hydraulic cylinder n the ram 0 of whiclfi gives passage to the guide'j, and has attached to its front end the four members pof a forked plunger, which pass through a ertures g in the flange 0 of the pointolder I) and are united at their frontends by a ring- 1' adapted to be reciprocated in the annular space between the cylinder q and pointholder 5.

For use, after the cable is has been introduced, molten lead is poured into the cylinder a through an aperture 8, which may be at or near the rear end thereof as shown in full lines, or at or near the front end thereof as shown at s, in broken lines, in which latter event a suitable valve or the like must be provided to close the pouring aperture 8 before the plunger 12 1" is operated. The solidified lead is then extruded by forcing forward the plunger lead being sufiicient to advancethe former.-

After the plunger 32 7' has been retracted more molten lead is poured into the cylinder (1 and oncoming into contact with the solid lead near the guide ring d left from the last operation, it melts the surface of said solid lead and welds therewith. The operation is then repeated until the desired length of cablehas been covered.

The only welding of lead necessary in the practical operation of this invention is transverse of the direction of extrusion and is effected by bringing molten lead into contact with solid lead.

As, in use, the working face of the plunger p 1' may become roughened by the adherence thereto of particles of lead, it is desirable to, provide means for giving access to said face so that it may be wiped. For this purpose the rear end of the cylinder a may be extended as at t, Figures 5 and 6, and lateral openings a formed in said extension, it being understood that, before molten lead is poured into the cylinder a, the plunger p 1' is advanced sufiiciently to close said openings u.

I claim:

1. A press for the continuous extrusion of lead sheathing on electric cables and the like comprising a cylinder adapted to be charged with molten lead, a supporting ring at the rear end of said cylinder, a tubularpoint holder supported so as to form an annular space within said cylinder by having its rear end mounted on said supporting ring, a plunger adapted to be reciprocated in said cylinder, said plunger having sector-like guide members adapted to slide through corresponding apertures in said supporting ring and an annular front end filling the annular space between said cylinder and said tubular point holder.

2. A press for the continuous extrusion of lead sheathing on electric cables and the like as claimed in claim 1, wherein the cylinder wall is formed with a charging aperture near its rear end for charging molten lead into the annular space of said 25 cylinder in front of said annular plunger.

ERNEST EDWARD JUDGE. 

